Structural integrity questions.

Having purchased this 17 Sport I've found a few causes for concerns and want to see what yalls opinions are.

First and for most the flex in the platform.
Derigged on the trailer lifting one hull a solid 18-24 inches before the other hull budges. Is this really that normal? I plan to re-bed the crossbars and inspect everything but there's no outward signed of damage. What's normal?

I have one cracked wing socket. Midway down. I understand it needs to be repaired, my question is can I still sit on it for my maiden voyage or leave them off?

The amount that the hulls twist relative to one another is somewhat dependent on how the boat is being supported, but 18"-24" sounds a bit excessive. I would say 6"-12" would be more normal.

The first thing I would do would be to pull off the tramp and remove the crossbars. Check the ends of each crossbar for cracks running parallel to the axis of the crossbar. A crack would allow the crossbar to spread open and twist around the corner casting. Next check the corner castings (the aluminum fittings that are screwed to the hull which the crossbars slip over). Most likely one or more of your corner castings have loosened up. These should be firmly mounted to the hull. If they are loose, it could be as simple as tightening the screws, but if the holes in the hull have worn out you may need to fill them with epoxy to reduce slop and/or possibly use larger screws.

As far as the wing tube, as long as the crack is in the middle of the tube it would be fine (other than letting water in). The top and bottom of the wing tube take all the load, the middle area just keeps it sealed.

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Good point.
Does anyone use shroud extenders since the 17 has a captive mast base?

Most people I know (including me) remove the pin after the mast is up. A pinned mast coming down will almost certainly trash the front crossbar - and they are no longer in production. (The extrusion die broke a while ago.)

If you weigh more than 165 lbs, you should be able to right the boat as long as the mast doesn't leak.

Another outstanding point! Thank you guys for your input. I am 155-160 lbs and well aquatinted with capsize procedures so maybe I can coax her up. I'll have to try it out.

I wanted to run the trap line outside of the wings but can only assume the chafe between the wing material and the bungee will make quick work of the bungee. How do y'all fight this or is it as simple as run the trap line inside the wings? And if that is the case do y'all have a different configuration of bungee that adds to the length of it to allow for a lot of movement fore and aft while on the wire?

You're right about the chafe between the wing/trap bungee. They tend to both get chewed up.

Most racers will tie a small single block on a ~4" long line to the bottom of the shroud adjuster on each side of the boat. The bungee runs through that to the trap extender line. Having the block on a leader helps prevent the trap wire from wrapping around the shroud.

There's generally no problem with the length of the bungee cord going forward or aft with this method.

Running the trap wire inside the wing is a better way to go. It's easier to reach the line to hook up (you're reaching in front of yourself, not behind). There's also nothing to hang up on the back of your life jacket or the hiking stick when you're sitting on the wing.

I'd recommend putting a 5" inspection port in each hull between the front crossbar and the shroud. This will give you access if you ever need to fix your forward wing tube or a cracked out centerboard well (they can crack where the spring sits). It will also give you a lot of in-boat storage and whatever you put in the hull will be trapped between the centerboard trunk and the front wing support, so it will stay put. If your boat leaks, you can also carry a sponge on board and sponge out water through the port (between races if you race). Lastly, this will give you access inside the hull so you can thru-bolt an eye strap with a small pulley to the deck a couple inches inboard and behind the shroud. You can pass your trap bungee through this pulley so the trap leads right to the outside edge of the hull (similar to using a cord tied to the bottom of the shroud adjuster that Matt recommended, but the setup is a little cleaner this way).

On my boat, I gain a little extra trap bungee length by tying a pulley to the underside of the aft tramp lacings and running the bungee back through this pulley so it forms a V under the tramp. This allows for a couple extra feet of bungee.

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Interesting thought. I do plan on adding the ports as I already have one cracked tube. I do have a fairlead in the hull lip just forward of the shroud and a single drilled hole in the transom lip. Reminded me of the trap bungee setup for the 18.
Any idea what this is for? Maybe previous owner added it? I also have the typical hole in the tramp for the bungee.

I have pulled apart the hulls and unsurprisingly all 4 caps fell right out. 2 stripped, the other two the screws backed all the way out. I plan to reinstall the screws that backed out and go with a larger diameter screws for the stripped out holes. Should I add anything to prevent them from backing out again? Also, what are they screwing into? Solid fiberglass or is there wood behind there? Crossbars are solid with minor SS vs Aluminum corrosion around the backing plate for the dolphin striker. Should this area be pulled all the way apart and re apply a teflon coating regularly? Any other areas that should be given extra attention or additional reinforcement while I have it apart?

I believe the screws for the crossbar castings just screw into fiberglass. Definitely not wood. Possibly some foam in there too, but not something that would add any holding power for the screws. I think bumping up to a larger screw size is the way to go. I have occasionally considered putting a flat washer and split lock washer under the screw heads to help hold them in, but since mine are still tight, I haven't bothered yet.

If the corrosion on your crossbars is minor and you plan to disassemble the boat anually, then I would say it is probably ok as is for now. Otherwise, I would remove the backing plates and apply a coating of tefgel. Tefgel works much better than the tape that is applied by the factory and it should more or less be a one-n-done process. Corrosion kills these parts and they are getting harder and harder to come by, so an ounce of prevention is well worth it.

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Given how easy it is to disassemble and the susceptibility of the crossbars and mountings I do plan to disassemble and inspect annually. I wondered about the backing that the screws go into to determine if I need to take extra precaution to seal from water intrusion. I guess I will anyways. The previous owner put a thick layer of what appears to be clear silicon caulk under the crossbars. What does everyone usually put down if anything? Is bedding with resin the way to go?

I don't think bedding with epoxy is really necessary (although some people do this) as long as the end caps are tight, the crossbar bolts are tight, and the tramp is tight. I wouldn't use and caulk under the crossbar. It will just make the boat harder to disassemble.

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Alright. Thanks for all your help. I'm not looking to race it in Nationals or anything. Just hot rod it around. Maybe a few local regattas.
Is there a torque spec for the crossbar bolts?

Hobie does not provide torque specs for any bolts (not really sure why). I generally just make the bolts as tight as possible using a T handle allen wrench. Be sure to put anti-seize on the bolts to prevent galling.

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Good call on the anti-seize. I fought for hours with one bolt before shearing it off.